Tokunaga Chiho, Matsushita Shonosuke, Sakamoto Hiroaki, Hyodo Kazuyuki, Kubota Misao, Tanioka Kenkichi, Hiramatsu Yuji
1 Department of Cardiovascular Surgery, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
2 Tsukuba University of Technology, Ibaraki, Japan.
Acta Radiol. 2018 Dec;59(12):1482-1486. doi: 10.1177/0284185118770892. Epub 2018 May 19.
Increased pulmonary blood flow (PBF) and shear stress may provoke irreversible vascular remodeling, yet invasive visualization of the microvasculature complicates monitoring. A non-invasive imaging methodology would therefore safely provide mechanistic insights into the progression of high PBF-induced vascular remodeling.
To establish a novel microvasculature visualization method using synchrotron radiation pulmonary microangiography (SRPA) that can also calculate PBF velocity in vivo.
A high PBF rat model was established by making a fistula between the abdominal aorta and inferior vena cava. After eight weeks, SRPA was performed and the dynamic density changes in the right lower pulmonary artery (PA) were calculated by software. SRPA was performed with a HARP (High-Gain Avalanche Rushing amorphous Photoconductor) receiver. PBF velocity was calculated by contrast medium transit time within the PA. All data were presented as mean ± standard error (SE). Student's t-test was used for comparison between the two groups.
High dynamic spatial and contrast resolution from SRPA in the PA allowed for clear pulmonary microangiography and accurate detection of higher PBF in the rat model (82.3 ± 8.5 mm/s high-PBF group vs. 46.1 ± 4.3 mm/s control group, P < 0.01).
These novel results demonstrate that SRPA was useful in both visualizing the dynamic flow distribution within the microvasculature and calculating PBF velocity. This newly developed, non-invasive technology may become a powerful tool in clarifying the mechanism of vascular remodeling associated with high PBF-induced shear stress.
肺血流量（PBF）增加和剪切应力可能引发不可逆的血管重塑，但微血管系统的侵入性可视化使监测变得复杂。因此，一种非侵入性成像方法将安全地提供有关高PBF诱导的血管重塑进展的机制性见解。
建立一种使用同步辐射肺微血管造影（SRPA）的新型微血管可视化方法，该方法还可以在体内计算PBF速度。
通过在腹主动脉和下腔静脉之间造瘘建立高PBF大鼠模型。八周后，进行SRPA，并通过软件计算右下肺动脉（PA）的动态密度变化。使用HARP（高增益雪崩快速非晶光电导体）接收器进行SRPA。通过PA内造影剂通过时间计算PBF速度。所有数据均以平均值±标准误差（SE）表示。采用学生t检验进行两组间比较。
PA中SRPA的高动态空间和对比度分辨率允许进行清晰的肺微血管造影，并准确检测大鼠模型中较高的PBF（高PBF组82.3±8.5mm/s vs.对照组46.1±4.3mm/s，P<0.01）。
这些新结果表明，SRPA在可视化微血管内的动态血流分布和计算PBF速度方面均有用。这种新开发的非侵入性技术可能成为阐明与高PBF诱导的剪切应力相关的血管重塑机制的有力工具。
